Testing

The electrical properties and dielectric strength of the transformers are tested by means of measurements and tests defined by international standards such as IEC, DIN, VDE, ANSI, NEMA, and BS. Summary of the tests are given as follows:

ROUTINE TESTS:
✔  Measurement of voltage ratio and check of vector relationship
✔  Measurement of winding resistance
✔  Measurement of impedance voltage and load loss
✔  Measurement of no-load loss and current
✔  Dielectric tests
✔  Separate-source voltage withstand test
✔  Induced over-voltage withstand test
✔  Partial discharge test*
* Special for oil type transformer

TYPE TESTS :
✔  Temperature rise test
✔  Lightning impulse test
✔  Measurement of acoustic sound level

SPECIAL TESTS:
✔  Measurement of zero-sequence impedance
✔  Measurement of the voltage and current harmonics
✔  Measurement of insulation resistance
✔  Measurement of capacitance and tan δ